SPEEA represents 23,000 Boeing engineers and technical workers, who are responsible for designing and testing Boeing aircraft. About 4,900 of the union’s 7,500 technical workers voted.

For Boeing, the favorable vote means it can now count on technical workers, as well as engineers, to help resolve 787 battery problems which grounded the fleet in January. The company is testing a redesigned battery with the hopes of returning the Dreamliner to passenger service.

“The votes by technical workers and engineers in recent weeks will allow us to come together and focus on the challenges and opportunities we face this year,” Ray Conner, president of Boeing Commercial Airplanes, said in a statement.

The contract ratified Monday includes 5 percent annual increases to wage pools and maintains health care without increasing member contributions. The major change, opposed by SPEEA leaders, is to retirement. New workers will be enrolled in a 401(k) plan rather than a defined pension.

The switch could create difficulties for SPEEA officials in future negotiations. SPEEA leaders previously said they suspect Boeing will freeze contributions to the pension plan when the union has more members under the 401(k) plan than the pension. They’ve worried about having a two-tier membership.

SPEEA leaders, who had encouraged in February union members to reject Boeing’s offer, emphasized the “gains” made since the company’s first offer, which was rejected by both engineers and technical workers in October. Union leaders had warned technical workers earlier this month that a lengthy strike would be required to force Boeing to change its mind.